sh: enable deferred io LCDC on Migo-R

Enable LCDC deferred io on Migo-R using 1s delay.

As with other deferred io frame buffers user space code should
use fsync() on the frame buffer device to trigger an update.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>